电选机电极结构对电场影响的研究分析

高压鼓式电选机在国内外均被广泛使用在物料的分离和分级中。特别在江西各钨矿和钽铌矿,高压鼓式电选机发挥了极为积极的作用。 电选过程是比较复杂的,除受矿粒电性的影响外,电极结构是影响电选的主要因     

混匀老系统端部料工艺改造

新(余)钢烧结厂老系统混匀采用的是人字形堆料法,取料机取到料条的端部时,只能取到表面一层或几层的物料,不能取到全断面所有料层的物料,因此端部料化学成分波动较大,换堆过程中对烧结矿成分的稳定影响较大。为此我厂借鉴新系统端部料改造的成功案例通过将取料机下一道工序的皮带与上堆料机的皮带用一根短程皮带连通,再通过堆料机将端部料均匀的加入到新混匀矿料条中。通过本次改造成功的改善了因端部料造成的混匀矿成份波动,稳定了烧结矿成分。     

简讯

首钢新2号高炉是目前国内首次使用皮带上料的无料钟炉顶高炉。为了准确地检测各种物料在皮带上的实际位置,首钢总计控室研制了上料皮带料位检测器,解决了皮带上物料的检测问题,为高炉的投产及正常运行提供了必不可少的条件。 新2高炉N_1上料皮带上有四个检测点,向上料控制系统发出实际物料位置检测信号,以确定何时开料仓闸门,向皮带上放料;何时开炉顶料罐上密,向料罐装料。如果信号误发,就会发生装重罐或把矿和焦撒落到炉顶料罐外面,以致影响生产。因此,皮带上的四个检测器是整个高炉上料系统的     

皮带溜槽的分选原理

概述皮带溜槽是选别细粒矿石的有效设备。分选在一无极的橡胶皮带构成的斜面上进行(见图1)。皮带以一定的速度向上方运动,给矿(矿浆)从斜面的中部给入,在斜面水流中重的矿粒就逐渐沉下,被皮带运上,经过精选段洗水的作用将其中的小比重矿物     

溜槽和离心选矿机中矿粒运动速度的计算

一、溜槽上矿粒运动速度溜槽是选别0.074～0.01毫米粒级物料的重要选矿设备之一。例如:普通溜槽、自动溜槽、皮带溜槽以及水力圓形矿泥淘汰盘等溜槽类型设备在钨、锡选矿厂中均有应用。有关溜槽上水流和矿粒的运动规律,除现有书上作了一些介绍外,近年来我国一些单位也作了报导。最近发表的资料(见《有     

电选中矿物荷电计算方法研究

本文通过对矿粒在鼓筒式高压电选机中荷电公式的理论推导,找出其中的不足,提出了一种把实验和计算机结合的方法来确定矿粒的荷电,从而指导电选生产。     

可升降调节布料装置

专利号:ZL200520042883.9专利权人:宝钢集团上海梅山有限公司发明(设计)人:朱存庭钟家伟赵国家贲仁海本实用新型涉及一种皮带机物料输送调节装置,特别涉及一种皮带输送机在输送物料过程中使物料能按预定要求落料的可升降调节布料装置。解决原料在落到皮带上时产生的粉尘,热返矿造成胶带损伤的技术问题。可升降调节布料装     

一种皮带运输机清扫器在泗洲选矿厂的应用

德兴铜矿泗洲选矿厂一期磨浮工段给料运输皮带在输送物料时有部分物料往往会粘结在胶带上,尤其物料水分较大时,在卸料端容易发生"返料"现象。长时间物料在卸料端下方堆积且皮带和托辊因接触不良发生"跑偏"现象,容易损伤皮带[1-2]。同时,机台的环境卫生治理也十分困难。因此清理回程胶带面上物料很有必要,为此在卸料滚筒部位自制安装清扫器,大大减少了运输皮带磨损,卸料端没有堆矿现象,也没有"跑偏"现象,取得了良好的效果。     

CTD-1224永磁大块干选机的研制及其发展

本文对永磁大块干选机的介绍,以及永磁大块干选机在选矿厂的应用前景分析,设计了一种处理量大、选别粒度大的CTD-1224永磁大块干选机,并进行设计分析。CTD-1224永磁大块干选机是目前国内研制的大处理量、大带宽的干选设备。该设备具有磁场强度高,选别深度深,结构合理,操作维修简单等特点。     

湿粘矿料在皮带系统长距离运送中的探索与研究

湿粘矿料在皮带系统中长距离运送是非常困难的,在国内乃至国际上都是难题,由于矿料湿粘、流动性差等原因,运送中常发生堵料情况造成皮带打滑、异常磨损、附件损坏等设备故障。本文叙述了湿粘矿料在皮带系统运送中遇到的困难和解决困难的研究、改造过程,摸索出了一系列改进方法和措施并最终成功解决了这一难题。     

微细粒贫铁矿石选矿技术攻关及工业实践

针对包钢白云鄂博西矿铁矿石中铁矿物嵌布粒度微细、需细磨至-45μm占85%才能有效解离的性质特点研究开发出了干式预选抛尾-阶段磨矿弱磁选、二段弱磁精上高频细筛(0.075 mm)、筛上产品再磨新工艺,尾矿高效浓缩干排干堆技术、回水净化技术及超长距离精矿矿浆输送技术并成功工业应用,实现了该类型铁矿石资源的高效开发利用。     

氧化锰尾砂回收利用的生产实践

用细粒强磁选对遵义锰矿氧化锰尾砂进行回收利用的生产实践表明，这既缓解了遵义锰矿入炉原料紧张的矛盾，又可使选矿车间获得较好的经济效益。     

缓冲床在带式输送机上的应用

针对传统带式输送机的不足,在物料落点用缓冲床代替传统的支承托辊,以避免物料下落冲击使输送带受损、防止物料散落的先进方案已被愈来愈多的使用者所接受,因此,采用该技术是未来带式输送机发展的一种趋势。     

废弃镁碳砖在中间包干式料中的应用研究

将整形和未整形的两种废弃镁碳砖回收颗粒(3～1mm)部分取代中档烧结镁砂颗粒(3～1mm)用于中间包干式料,研究了两种颗粒加入量的不同对干式料性能的影响。结果表明:整形和未整形颗粒均可用于中间包干式料,整形后颗粒加入量不宜超过30%,未整形颗粒加入量不宜超过15%。将添加30%整形颗粒的中间包干式料用于转炉中间包,可满足现有连铸工艺要求,达到原有干式料的使用效果。     

鹤庆县锰矿人工柱锚杆房柱法试验研究

介绍了在鹤庆县锰矿缓倾斜厚矿体中,试验成功的人工柱锚杆房柱采矿法。其特点是,采用人工柱替代矿石柱,锚杆网支护不稳固顶板,大幅度地提高了矿石回采率。经过11个矿房的试验回采,取得了较好的经济效益。     

Blast furnace circumferential process symmetry: effect of flow distribution in hot blast systems

Abstract

Solid particle flow patterns in the moving bed zone of a melter/gasifier were studied using discrete element method (DEM). Interparticle forces were calculated using the Hertz–Mindlin no slip contact model. The simulation results of the solid particle flow patterns agree well with the experimental results exhibited by tracer particles. The solid particle flow pattern and descending velocity were studied, as well as the effect of the discharge rate of solid particles in the raceway on solid particle flow pattern in the moving bed.

Results show that the moving bed could be divided into four subdomains based on the velocity of solid particles. A stagnation zone with semielliptic geometry is formed at the central bottom of the moving bed during drainage of solid particles. Furthermore, the simulated results of compressive force among solid particles in the moving bed zone indicate that the deadman zone undergoes a high degree of compressive force, especially at the centre of the gasifier. This finding implies that more compressive force resistant solid material should be placed at the centre zone by manipulating solid particles fed into the melter/gasifier.     

Dam-Break Wave-Front Celerity

This work is concerned with the role that friction and inertia effects can play on the magnitude of dam-break wave-front celerity. Classic analytical solutions are presented. A large collection of experimental data is used, covering a wide range of different initial conditions: fixed bed or mobile bed (five types of bed material), dry or wet bed downstream, and with or without bed step. To overcome the limitations of analytical solutions, a numerical model is used. The model is based on the shallow-water approach with contact-load dominated sediment transport, and it makes use of developments recently made in the study of sheet flows. The analytical and numerical results are compared with experimental data. It was found that the celerity is mainly dictated by the friction coefficient, by the sediment inertia, by the initial downstream water depth, and by the initial bed step height. For good data fitting, the friction coefficient must be influenced by the type of bed, fixed or mobile. In the latter, the coefficient must vary with the bed material characteristics. The dissimilarities between the experimental, analytical, and numerical results are interpreted.     

酸性物料的粒度对承钢分流制粒厚料层烧结的影响

研究了承钢分流制粒厚料层酸性物料粒度对烧结工艺的影响。大粒度物料能改善料层的透气性,有利于厚料层的应用。酸性物料的粒度较大时,矿相里有大量集中分布的赤铁矿,局部形成交织熔蚀结构,能极大的改善钒钛磁铁矿的冶金性能。     

烧结一次混合机系统工艺优化改造

由于烧结生产的特殊性,生石灰、白云石及除尘灰等小颗粒干物料用量较大,在皮带机倒运过程中,导致一次混合机区域产生大量粉尘,粉尘排放浓度严重超标,操作环境极差,通过对原一艺布局进行优化改造并对混合机进料端进行整改后,区域扬尘现象得到有效遏制。     

Evaluation of Ilmenite as Dense Medium for Dry Coal Fluidized Bed Beneficiation

ABSTRACT

Published work on dry dense medium fluidized beds has mainly used magnetite and fine coal to make up the dense medium. Magnetite is used to achieve the required cut densities, but its recovery and reuse are problematic because it attaches to the surface of the coal and discard material, and its surfaces become contaminated. This study focused on using ilmenite (FeTiO₃) as an alternative medium in the dry dense medium fluidization process due to its favorable surface properties of hydrophilic and sphericity. The initial investigation considered a reference medium, which consisted of ilmenite and sand (used for base-case tests), and a second medium, consisting of ilmenite and fine coal, which resembled that currently used in the dry dense medium fluidized bed process. Experiments to evaluate the performance of the ilmenite were carried out in a laboratory-scale cylindrical fluidized bed. Losses of the ilmenite were investigated by mixing and recovering the ilmenite using two different coal samples of 13.2–50 mm particle size. Density tracers were used to determine the écart probable moyen (EPM). At optimal conditions, the bed media consisting of sand and fine coal with ilmenite had EPM values of 0.045 and 0.05 at cut densities of 1.8 and 1.58 g/cm³, respectively. No ilmenite losses were observed. The ilmenite surfaces contained no contaminants after 10 cycles. The highest ilmenite recovery achieved from the bed after high-intensity magnetic separation was 99.79%.